The present invention relates to an apparatus for adjusting a vehicle body height.
A motor vehicle is generally equipped with a wheel suspension device including an air suspension utilizing the volumetric elasticity of air. Air suspensions are disposed for the front and rear wheels on both sides. A sensor for detecting a vehicle body height is mounted to each of the air suspensions. Each of the vehicle body height sensor transmits signal for adjusting the vehicle body height so as to displace the vehicle body upwardly or downwardly by supplying air into or letting the air out of the air suspension.
An apparatus adjusting for is provided with a switching means for changing the vehicle body height from a normal height to a high height or to a low height. By switching means, when the vehicle is running on a rough road, the vehicle body is raised higher than a normal to prevent the vehicle body from touching the road. On the other hand, when the vehicle is running on a paved even road such as a highway, the vehicle body is lowered to attain running stability at high speeds. Such an apparatus for adjusting the body height described is disclosed in the Japanese Patent Laid-open Publication (KOKAI) No. 60-191810.
The height adjusting of the vehicle body is usually carried out for about 20 to 30 sec. regardless of the vehicle speed. But this may depend on the air supplying or removing capacity of the air suspension. The vehicle body height adjusting action cannot be generally felt by a driver or others. And there remains uncertainty as to whether or not the vehicle body height adjustment has been surely made. In order to overcome this problem, it may be considered to shorten the vehicle body height changing action. However, in case where such vehicle body height changing action is made rapidly regardless of the vehicle speed, the rapid change of the vehicle body height will give a sense of uneasiness to the driver.